1. Field of the Invention
The present invention relates to a needle bar thread guide device for a sewing machine.
2. Description and Problems of the Related Art
A conventional sewing machine, for example, a conventional industrial lockstitch sewing machine is provided with a needle bar thread guide at the lower end portion of a needle bar. When such a sewing machine is equipped with a thread trimming device, it is desirous that a needle thread end which has been trimmed by the thread trimming device remains on the needle side to be as short as possible so long as the stitch of the next sewn product is acceptable at the starting portion thereof. When, for this reason, the thread is adjusted that the needle thread end remains short on the needle side after trimming, the needle thread is liable to come off a needle eye at the start of next sewing. Particularly in a rotary thread take-up type high-speed zigzag sewing machine, the needle thread is liable to come off the needle eye at the start of next sewing in case of some kinds of sewing material or thread so that it is no more possible to continue sewing since the needle thread is pulled up by the rotary thread take-up rapidly and in large quantities. The conventional needle bar thread guide only functions to prevent the needle thread from slackening and to guide the same to the needle eye correctly, but has substantially no function to apply a frictional resistance thereto to prevent the same from coming off the needle eye.